The following abbreviations are herewith defined, at least some of which are referred to within the following description.
3GPP Third Generation Partnership Project
ACK Positive-Acknowledgment
ANDSF Access Network Discovery and Selection Function
AP Access Point
APN Access Point Name
BLER Block Error Ratio
BPSK Binary Phase Shift Keying
CAZAC Constant Amplitude Zero Auto Correction
CCA Clear Channel Assessment
CCE Control Channel Element
CP Cyclic Prefix
CQI Channel Quality Indicator
CSI Channel State Information
CSS Common Search Space
D2D Device-to-Device
DCI Downlink Control Information
DL Downlink
DMRS Demodulation Reference Signal
eNB Evolved Node B
EPDCCH Enhanced Physical Downlink Control Channel
E-RAB E-UTRAN Radio Access Bearer
ETSI European Telecommunications Standards Institute
E-UTRAN Evolved Universal Terrestrial Radio Access Network
FBE Frame Based Equipment
FDD Frequency Division Duplex
FDM Frequency Division Multiplexing
FDMA Frequency Division Multiple Access
FEC Forward Error Correction
GPRS General Packet Radio Service
GPT GPRS Tunneling Protocol
HARQ Hybrid Automatic Repeat Request
H-PLMN Home Public Land Mobile Network
IP Internet Protocol
ISRP Inter-System Routing Policy
LAA Licensed Assisted Access
LBE Load Based Equipment
LBT Listen-Before-Talk
LTE Long Term Evolution
MCL Minimum Coupling Loss
MCS Modulation and Coding Scheme
MME Mobility Management Entity
MU-MIMO Multi-User, Multiple-Input, Multiple-Output
NACK or NAK Negative-Acknowledgment
NAS Non-Access Stratum
NBIFOM Network-Based IP Flow Mobility
OFDM Orthogonal Frequency Division Multiplexing
PCell Primary Cell
PBCH Physical Broadcast Channel
PCO Protocol Configuration Options
PCRF Policy and Charging Rules Function
PDCCH Physical Downlink Control Channel
PDCP Packet Data Convergence Protocol
PDN Packet Data Network
PDSCH Physical Downlink Shared Channel
PDU Protocol Data Unit
PGW Packet Data Network Gateway
PHICH Physical Hybrid ARQ Indicator Channel
PLMN Public Land Mobile Network
PMI Precoding Matrix Indicator
PRACH Physical Random Access Channel
PRB Physical Resource Block
PTI Procedure Transaction Identity
PUCCH Physical Uplink Control Channel
PUSCH Physical Uplink Shared Channel
QoS Quality of Service
QPSK Quadrature Phase Shift Keying
RAB Radio Access Bearer
RAN Radio Access Network
RAR Random Access Response
RE Resource Element
RI Rank Indicator
RRC Radio Resource Control
RX Receive
SA Scheduling Assignment
SC-FDMA Single Carrier Frequency Division Multiple Access
SCell Secondary Cell
SCH Shared Channel
SGW Serving Gateway
SIB System Information Block
SINR Signal-to-Interference-Plus-Noise Ratio
SR Scheduling Request
TAU Tracking Area Update
TB Transport Block
TBS Transport Block Size
TCP Transmission Control Protocol
TDD Time-Division Duplex
TDM Time Division Multiplex
TEID Tunnel Endpoint Identification (“ID”)
TRU Transmission Resource Unit
TX Transmit
UCI Uplink Control Information
UE User Entity/Equipment (Mobile Terminal)
UL Uplink
UMTS Universal Mobile Telecommunications System
V2I Vehicle-to-Infrastructure
V2N Vehicle-to-Network
V2P Vehicle-to-Pedestrian
V2X Vehicle-to-X
V2V Vehicle-to-Vehicle
V-PLMN Visited Public Land Mobile Network
WiMAX Worldwide Interoperability for Microwave Access
WLAN Wireless Local Area Network
In wireless communications networks, V2X transmission and reception may be used. Resource allocation for V2X may be performed by eNB scheduling and/or by UE autonomous selection. eNB scheduling may work for in-network coverage scenarios in which the eNB can schedule the resource for served UEs taking into account various latency requirements of different services between the eNB and the UEs. UE autonomous resource selection may work for out-of-network coverage and may work for in-network coverage. In certain configurations, a UE may autonomously select a needed resource from a preconfigured resource pool with an equal probability for using each resource without a resource collision. As may be appreciated, eNB scheduling may be preferred in certain configurations because eNB scheduling may avoid possible resource collision that can happen in UE autonomous resource selection. In contrast, UE autonomous resource selection may be preferred in certain configurations because UE autonomous resource selection may save signaling overhead and work for out-of-network coverage.
In one configuration, an SA pool and its associated data pool may be time-multiplexed and located in different subframes. In such a configuration, the SA pool may be located before the associated data pool in the time domain. In some configurations, a minimum time period for transmission of the SA pool may be 40 ms. Even with the lowest SA pool time period, a UE may need to wait 40 ms to transmit one time. Accordingly, with such wait time, low latency requirements of V2X transmission may not be met. Moreover, in some configurations, a UE may randomly select a resource for SA transmission and its associated data transmission. Therefore, a first resource collision may occur for the randomly selected resource for SA transmission and a second resource collision may occur for the randomly selected associated data transmission.